Pole-joint and method of making same.



JOHN A. McCULLOCI-I, 0F VERSAILLES, PENNSYLVANIA, ASSIGNOR T0 NATIONAL TUBE COMPANY, OF PITTSBURGH, PENNSYLVANIA, A CORPORATION OF NEW JERSEY.

POLE-JOINT AND METHOD OF MAKING SAME.

Specification of Letters Patent.

Patented Apr. 18, 1916.

Application filed August 29, 1914. Serial No. 859,168.

My invention relates to the manufacture of poles formed of wrought metal pipes or tubes, and more particularly relates to the .manufacture of such poles which are made in transversely divided sections with the end of one section telescoped within the end of another section and the encircling end of one section of the pole pipe swaged on the telescoped end of another section. Heretofore in making such poles it has been the practice to swage the encircling end of the sections tightly into frictional engagement with the cylindrical surface of the telescoped end ofthe adjoining section. Such poles have not been found entirely satisfactory as the joints sometimes are loose or become loosened after the poles have been com- .pleted to an extent sufficient to permit of telescoping or relative lengthwise movement of the sections, which changes the overall length of the poles and makes them unfit for the use for which they were intended.

One object of myinvention is to provide a tubular wrought metal pole, made in sections as heretofore'and having the end of one sectionsecured to the adjoining end of the next section in such manner as will remove any liability of the joints becoming loosened with distortion or displacement of the metal in the contacting surfaces at the joints and thereby overcome the possibility of one section of the pole telescoping farther on or in the adjoining section to which it is connected.

Another object of my invention is to provide a novel method of making tubular, wrought metal, sectional poles whereby the pipe sections are fastened together much more securely than by the methods heretofore used and without material increase in the cost of making the poles.

Still further objects of the invention will become apparent hereinafter as the invention is more fully disclosed in the specifica vtion and pointed out in the appended claims. Referring to the accompanying drawings, forming part of this specification, Flgure 1 is a longitudinal plan showing a sectional tubular pole constructed and arranged in accordance with this invention. Fig. 2 is a sectional plan showing one manner of formmg the joints between the sections of the pole in accordance with my invention. Fig. 3 IS a detail sectional plan showing the construction and arrangement of the grooves formed in the telescoped ends of the sections in forming poles with the joint of Fig. 2-. Fig. 4. is a sectional plan, similar to that shown in Fig. 2 showing a modified and the preferred manner of constructing the joints between the sections of the pole in accordance with this invention. Fig. 5 is a detail sectional plan, similar to that shown in Fig. 3, showing the preferred way of scoring or raising the surface of the telescoped ends of the pipe sections in forming joints like that illustrated in Fig. 4.

In the drawings referring now to Figs. 1, 2 and 3, a tubular pole is shown whichis formed of wrought metal pipe and which comprises the sections 2, 3 and 4. The top or upper section 2 is smaller and the bottom section 4 is larger in diameter than the intermediate section 3, so that one end of the section 2 extends within the adjacent end of the section 3, and the encircling end portion of the section 3 is swaged to a diameter smaller than the balance of this section so that its inner surface tightly engages the outer surfaces of the ridges 5 between the grooves 6 in the telescoped end of the top section 2. The inequalities in the rough surface on the. interior of the encircling end of the sections ordinarily is sufiicient, when the telescoped ends of the sections are grooved in the manner shown in Figs. 2 and 3 to securely hold one section in engagement with the adjacent section. In a similar manner. the one end of the section 4 is swaged to a smaller diameter so as to cause its inner surface to tightly grip the outer surface of the ridges 5 between the grooves 6 in the telescoped end of the section 3 of the pole.

In the construction shown in Figs. 4 and 5 the 'telescoped ends of the pipes are scored to form a series of grooves 6 with ridges 5 therebetween which are wedge shaped or pointed in cross section and in forming grooved surfaces like that shown in Fig; 4, and, in detail in Fig. 5, the metal is displaced instead of cutting away the metal in forming {the grooves between adjacent ridges, as in Figs. 2 and 3.

Before assembling the pole sections in making poles with joints like that illustrated in Figs. 2 and 3 in the manner described, one end of the section 2, (the end which telescopes within the swaged end of the section 3) and the one end of the section in the swaged end of an adjoining section.

In preparing the sections for making poles having joints like that shown in Figs. 4 and 5, the ends of the sections 2 or 3 to be telescoped are scored to displace the metal without cutting or nachining'the metal to form the grooves 6?. One way of doing this is to rotate the pipe and bring the peripheral edge of a rotating'wheel or disk into engagement with the surface to be scored, the disk cutting into and raising or displacing the metal .to form the ridges 5 k The so-scored or grooved end of each section of the pole is then inserted or telescoped within the end of a section to be swaged on The swaged end of the section of the pipe is-heated prior to the swaging operation and after the two sections are positioned in the desired relation, the swaging operation is performed in the same manner as1 heretofore in forming such sectional p0 eSq In swaging the end. of one section of the pole on the scored or grooved end of the telescoped section, the metal on the inner surface of the swaged end of the pipe will be displaced and will be forced into the scores or grooves 5 on the outer surface of-the telescoped section, so that after the completion of the swaging operation the possibility of endwise movement of one section relative to the other is materially lessened, if not entirely prevented.

shown in Figs. 2 and 3, the metal of the encircling ends of the sections will not be' forced into the grooves 6 to an appreciable-extent, but in such event the rough surface will be found suflicient to hold the sectionsin engagement; In joints formed as 7 shown in Figs. .4 and 5 the relatively sharp apices of the ridges 5 will be forced intothe contacting surfaces of the swaged or encircling pole section, in the manner illustrated.

Preferably but a portion of the telescoped section is cylindrical.

In some cases in forming joints like that.

end of each section is grooved or scored, so

that the telescoped endof the section contacting with the outer end of the swaged The grooves 5 and 5 may, however, when desired, be extended to the full length of the telescoped end of the pipe so as to be in engagement with the swaged end of the other section of the pipe for the full length of the telescoping portions of the sections.

The advantages of my invention will be apparent to those skilled in the art. By scoring or grooving the telescoped end of each section of the pole and swaging the engaging or encircling end of the adjacent section of the pole on the grooved or scored surface, the possibility of one section of the pole moving endwise relatively to the one to which it is attached is lessened, if 'not entirely prevented.

Modifications in the construction and arrangementof the parts in constructing the joints of the tubular sectional poles and in the means for grooving or scoring the sections may be made without departing from my invention as defined in the appended claims. I

I claim:

1. A hollow wrought metal pole, formed in sections and having the end of one section telescoped within the end of the adjoin-' ing section, with the encircling end of said adjoining section swaged into close contact with the telescoped end of said telescoping section, and with the engaging surfaces of said telescoped ends roughened to formregistering ridges and grooves whereby relative movement of the sections at the soformed .joint is prevented. j 2. The method of forming hollow sectional wrought metal poles which consists in forminga series of ridges and grooves on the end of one section of the pole and swaging the surface of the encircling end of the adjoining section into close contact with the ridges of the other section of the pole.

3. The method of forming hollow sectional wrought metal poles which consists in forming a series of encircling grooves on the telescoped end of one section of the pole and swaging the encircling end of the adjoining section into close contact with the grooved end of said section and forcing the metal of the swaged section into the grooves between the ridges on the end of the telescoped section of the pole.

In testimony whereof, I have hereunto set my hand.

JOHN A. MCCULLOOH, WVitnesses:

Jns. PVDAVIST' CHAs. STARR. 

